Monday, February 16, 2015

This is an intriguing study out of UC Irvine with results reported in the February 15, 2015 issue of Cancer Research. I'm wondering if there's a window of opportunity. For example, were this to be valid for human trial, would transplantation reverse "chemo brain" in those still struggling years after cancer treatment? I hope research continues with success...Idelle

See more below in this press release from the American Assoc. for the Advancement of Science (AAAS).

In preclinical studies using rodents, they found that stem cells transplanted one week after the completion of a series of chemotherapy sessions restored a range of cognitive functions, as measured one month later using a comprehensive platform of behavioral testing. In contrast, rats not treated with stem cells showed significant learning and memory impairment.

The frequent use of chemotherapy to combat multiple cancers can produce severe cognitive dysfunction, often referred to as "chemo brain," which can persist and manifest in many ways long after the end of treatments in as many as 75 percent of survivors - a problem of particular concern with pediatric patients.

"Our findings provide the first solid evidence that transplantation of human neural stem cells can be used to reverse chemotherapeutic-induced damage of healthy tissue in the brain," said Charles Limoli, a UCI professor of radiation oncology.

Many chemotherapeutic agents used to treat disparate cancer types trigger inflammation in the hippocampus, a cerebral region responsible for many cognitive abilities, such as learning and memory. This inflammation can destroy neurons and other cell types in the brain.

Additionally, these toxic compounds damage the connective structure of neurons, called dendrites and axons, and alter the integrity of synapses - the vital links that permit neurons to pass electrical and chemical signals throughout the brain. Limoli compares the process to a tree being pruned of its branches and leaves.

Consequently, the affected neurons are less able to transmit important neural messages that underpin learning and memory.

For the UCI study, adult neural stem cells were transplanted into the brains of rats after chemotherapy. They migrated throughout the hippocampus, where they survived and differentiated into multiple neural cell types. Additionally, these cells triggered the secretion of neurotrophic growth factors that helped rebuild wounded neurons.

Importantly, Limoli and his colleagues found that engrafted cells protected the host neurons, thereby preventing the loss or promoting the repair of damaged neurons and their finer structural elements, referred to as dendritic spines.

"This research suggests that stem cell therapies may one day be implemented in the clinic to provide relief to patients suffering from cognitive impairments incurred as a result of their cancer treatments," Limoli said. "While much work remains, a clinical trial analyzing the safety of such approaches may be possible within a few years."